Wilh. Wilhelmsen Holding ASA (WWH) is a Norwegian multinational maritime group, headquartered in Lysaker, Norway. The group employs more than 21,000 people and has operations in 75 nations. The Wilhelmsen group operates the largest maritime network in the world, with over 2200 locations worldwide.

The WW group was founded on 1 October 1861 in Tønsberg. The company's first vessel was the barque Mathilde in 1886. Halfdan Wilhelmsen was forward thinking and realised that steamboats were the future, therefore in 1887 he bought the vessel Talabot. It was only after they bought Talabot that the company started making profits. Thence, all their ships have been named, started with the letter "T", often leading to the same name given repeatedly to different ships over time. For example, there have been at least four ships named Talabot ranging from tankers to ro-ro vessels.

Since 1978 the main owners have been the siblings Cecilie Paus and Helen Juell, and their now deceased brothers Wilhelm Wilhelmsen and Finn Wilhelmsen. Their children, the fifth generation of the Wilhelmsen family, are Thomas Wilhelmsen, Olympia Paus, Pontine Paus, Cathrine Løvenskiold Wilhelmsen, Hedvig Juell, Maren Juell, Hannah Wilhelmsen, Monica Wilhelmsen and Julie Wilhelmsen.

In 1861, the company was founded by (Morten) Wilhelm Wilhelmsen in the town of Tønsberg, Norway. During the next two decades, Wilhelmsen's fleet increased with an average of one ship per year and by 1886 Wilhelmsen was Tønsberg's largest shipowner.

In 1886, Wilhelmsen's eldest son, Halfdan Wilhelmsen joined the firm and was instrumental in the company's move from sail ships to its first steamship. In late 1887, the company acquired the 1,800-ton freighter, Talabot. The steamship was a profitable investment for the Wilhelmsens and the letter "T" became synonymous with the company's naming tradition for its vessels.

In 1890, Halfdan Wilhelmsen laid the basis of the company's core business - liner trades. In 1911 NAAL (The Norwegian Africa and Australia Line) was established.

A turning point in the expansion of the Roll-on/roll-off operations was the full acquisition in November 1995 of NAL (Norwegian America Line) and its 7 Car Carriers. NAL also owned a 70% stake in NOSAC (Norwegian Specialised Autocarcarriers), already in partnership with Wilh. Wilhelmsen Line, that was owning the remaining 30% share. At that time, NAL was facing a cargo volume downturn and an overall profits reduction, that made register lower than expected financial results in 1994-1995. However the NOSAC takeover was fundamental not only to increase the fleet of nearly further 20 Car Carrier vessels, but also to fully step into the Korean market, where the company was previously awarded Kia Motors contract to ship cars from South Korea to United States, from 1996 to 1998.

The company's owners, the Wilhelmsen family, are descended from Wilhelm Zachariassen Holst (ca. 1732–1807), who worked at Vallø saltverk. His great-grandson was shipping magnate (Morten) Wilhelm Wilhelmsen (1839–1910), the founder of Wilh. Wilhelmsen. He was the father of ship-owner Halfdan Wilhelmsen (1864–1923), factory owner Finn Wilhelmsen (1867–1951), ship-owner Wilhelm Wilhelmsen (1872–1955) and businessman Axel Wilhelmsen (1881–1957).